Many bacteria that are pathogenic to man and beast employ menaquinone (vitamin K2) as a component of their electron transport chain. This chain provides the organism energy. Menaquinones are biosynthesized from shikimic acid and glutamic acid, by a pathway which is not yet completely understood. This project seeks to remedy this situation, and use knowledge of the structure of the various intermediates to design inhibitors of the pathway. Thereby, it is hoped to produce specific chemical antagonists of menaquinone-requiring organisms. The pathway will be studied first in cuttings and root cultures of Impatiens balsamina; this plant produces lawsone (2-hydroxy-1,4- naphthoquinone) whose biosynthesis parallels closely that of menaquinone. Results obtained in this system will be checked in the bacteria Mycobacterium phlei, Corynebacterium diphtheriae, Bacillus megaterium, and Staphylococcus aureus. Biosynthetic studies will rely heavily on the use of a computerized combined radio gas chromatograph- mass spectrometer and mathematic modelling.